1. Field Of The Invention
This invention relates to a hub assembly for a wheel of a motor vehicle, the assembly comprising a hub member, a double row rolling-element bearing having at least one inner bearing ring which is separate from the hub member and received thereon, and a constant velocity ratio universal joint member, connected to the hub member for driving it. More particularly, the invention relates to the holding of such separate inner bearing ring in the desired position on the hub member so that the bearing is correctly set, which may be such that the bearing is preloaded.
2. Description Of Prior Art
Hub assemblies are known wherein a simplification and reduction in the number of separate parts is achieved by having the hub member formed integrally with the universal joint member, which usually is the outer member of a constant velocity ratio universal joint. Such an integral component may further be integral with a flange member for wheel attachment, but such a construction has disadvantages with respect to the bearing. In particular, the number of rolling elements (balls or taper rollers) which may be provided in each row of the bearing is limited, so the load carrying capacity of the bearing is limited. Further, bearing size is dependent upon the size of the outer joint member, inhibiting freedom of design.
Hub assemblies are known wherein the outer joint member and the hub member are connected so as to be separable, and the row of bearing elements adjacent the joint member engages an inner bearing ring which is a separate component. The inner bearing ring for the other row of bearing elements may also be separate. Such an arrangement permits the greatest possible degree of filling, i.e. the maximum number of rolling elements, in the bearing, so that a high capacity of bearing of small dimensions is obtained. The disadvantage is that the inner bearing ring or rings have to be held on the hub member, usually in such a way that the bearing is preloaded, which typically requires the provision of further components. The arrangement can be simplified by having the bearing preloaded by whatever means connects the joint member and hub member, e.g. by having the joint member abut the adjacent inner bearing ring. Such arrangements, however, turn out to be expensive, and there is the possibility of backlash in the torque transmitting connection between the joint and hub member, and bearing failure resulting from settling of the components after assembly thereof.
In DE-3418440 a hub assembly is proposed wherein the hub member has a separate inner bearing ring secured by hot forming the hub member, the hub member being removably connected to the universal joint member. Such an arrangement still requires the provision, e.g. of interengagable teeth and a fastening bolt or bolts between the hub member and joint member, so offers no reduction in cost or complexity.